Add samples and variance support

pennylane_qiskit/aer.py

@@ -63,6 +63,7 @@ class AerDevice(QiskitDevice):
         compile_backend (BaseBackend): The backend used for compilation. If you wish
             to simulate a device compliant circuit, you can specify a backend here.
     """
+
     # pylint: disable=too-many-arguments
 
     short_name = "qiskit.aer"
@@ -73,15 +74,17 @@ def __init__(
         shots=1024,
         backend="qasm_simulator",
         noise_model=None,
-        backend_options=None,
         **kwargs
     ):
         super().__init__(wires, qiskit.Aer, backend=backend, shots=shots, **kwargs)
         self._noise_model = noise_model
-        self._backend_options = backend_options
 
     def run(self, qobj):
+        """Run the compiled circuit, and query the result."""
         self._current_job = self.backend.run(
             qobj, noise_model=self._noise_model, backend_options=self.kwargs
         )
-        self._current_job.result()
+        result = self._current_job.result()
+
+        if self.backend_name in self._state_backends:
+            self._state = self._get_state(result)

pennylane_qiskit/ibmq.py

@@ -68,7 +68,6 @@ class IBMQDevice(QiskitDevice):
     """
 
     short_name = "qiskit.ibmq"
-    _backend_kwargs = ["verbose", "backend", "ibmqx_token", "ibmqx_url"]
 
     def __init__(self, wires, provider=None, backend="ibmq_qasm_simulator", shots=1024, **kwargs):
         token = os.getenv("IBMQX_TOKEN") or kwargs.get("ibmqx_token", None)